What is the study of plate tectonics primarily concerned with?

The study of plate tectonics is fundamentally focused on the movement of the Earth’s lithosphere plates. This concept encompasses various geological phenomena such as earthquakes, volcanic activity, and the formation of mountains and oceanic trenches, all of which are intrinsic to the dynamics of the Earth's surface. The lithosphere is divided into several tectonic plates that interact at their boundaries, leading to various geological processes and structures.

Understanding these movements helps explain how continents drift, the formation of new crust at mid-ocean ridges, and the recycling of crust at subduction zones. This foundational concept in geology provides insights into both the historical development of the Earth's surface and the processes that continue to shape it today.

The other options, while related to Earth's features and processes, do not capture the primary focus of plate tectonics. For instance, the structure of the Earth’s core pertains to a different aspect of geology. Erosion and sedimentation concern surface processes rather than the dynamics of the lithosphere. Climatic changes involve atmospheric conditions and are not directly linked to the mechanics of tectonic movement, even though tectonics can influence climate over geological timescales.